Murine type II collagen arthritis. Association of an acute-phase response with clinical course

Bacterial lipopolysaccharide potentiates type II collagen-induced arthritis in mice

Collagen-induced arthritis (CIA) is an immunologically relevant animal model of human rheumatoid arthritis. Studies comparing the disease incidence in genetically susceptible male and female DBA/1LacJ mice demonstrated that under low density/low stress housing conditions, female mice had earlier onset (day 35) and higher disease incidence (25%) than the male mice (17% at day 49) when immunized with bovine type II collagen. A single subcutaneous or intraperitoneal injection of bacterial lipopolysaccharide (LPS) 17–24 days after collagen immunization greatly potentiated this standard CIA model in a dose related manner. 20–40 μg of LPS accelerated the onset of disease from day 35 to day 21 and exacerbated the clinical severity score from 0.27 to 2.00 at day 42. A similar administration of 6 μg of recombinant interleukin-β produced a comparable potentiated CIA model. The acute phase protein, serum amyloid P (SAP), was elevated in the serum at day 26 to 440 μg ml⁻¹ for the LPS potentiated CIA mice compared to 65 μg ml⁻¹ in the non-potentiated immunized CIA mice. There was a significant correlation (r = 0.78) between SAP levels and disease expression in the LPS treated CIA mice. The rapidity and uniformity of disease expression in this LPS potentiated CIA model will allow more and different drugs to be evaluated with a smaller number of animals.

Evaluation of TNF-alpha and IL-1 blockade in collagen-induced arthritis and comparison with combined anti-TNF-alpha/anti-CD4 therapy

We have evaluated the effects of anti-TNF-alpha, anti-IL-1, and combined anti-TNF-alpha/anti-CD4 therapy in collagen-induced arthritis. Blockade of TNF-alpha or IL-1 before disease onset delayed, but did not prevent, the induction of arthritis. When treatment was initiated after onset of arthritis, anti-TNF-alpha, anti-IL-1beta, and anti-IL-1R (which blocks IL-1alpha and IL-1beta) were all found to be effective in reducing the severity of arthritis, with anti-IL-1R and anti-IL-1beta showing greater efficacy than anti-TNF-alpha. Anti-IL-1beta was equally as effective as anti-IL-1R, indicating that IL-1beta plays a more prominent role than IL-1alpha in collagen-induced arthritis. An additive effect was observed between anti-TNF-alpha and anti-IL-1R in the prevention of joint erosion and in normalization of the levels of serum amyloid P. Combined anti-TNF-alpha/anti-CD4 therapy also caused normalization of serum amyloid P levels. The therapeutic effect of anti-TNF-alpha plus anti-CD4 was comparable to that of anti-TNF-alpha plus anti-IL-1R, suggesting that combined anti-TNF-alpha/anti-CD4 therapy prevents both TNF-alpha- and IL-1-mediated pathology. Anti-TNF-alpha treatment reduced IL-1beta expression in the joint and, conversely, anti-IL-1beta treatment reduced TNF-alpha expression. Combined anti-TNF-alpha/anti-CD4 treatment almost completely blocked the expression of IL-1beta, thereby confirming the ability of this form of combination therapy to prevent IL-1ss-mediated pathology.

Influence of long term silicone implantation on type II collagen induced arthritis in mice

OBJECTIVES

The use of silicone implants in cosmetic and reconstructive surgery has been implicated in the development of autoimmune connective tissue diseases. Previous investigation of the influence of short-term silicone implantation using an experimental model of rheumatoid arthritis revealed no adverse influence upon disease despite the generation of autoantibodies against silicone bound proteins. This study was designed to examine the influence of long term implantation of different forms of silicone in collagen induced arthritis.

METHODS

DBA/1 mice were surgically implanted with silicone elastomers, gel or oil nine months before immunisation with type II collagen emulsified in Freund's incomplete adjuvant. The incidence and severity of arthritis, antibodies to type II collagen, and serum cytokines were assessed and compared with sham implanted mice. Silicone implants were recovered, and autoantibodies to silicone bound proteins evaluated in arthritic and non-arthritic mice.

RESULTS

Immunisation with CII/FIA resulted in a 30% arthritis incidence in sham implanted DBA/1 mice. Long term silicone implantation resulted in an increased incidence of arthritis, with a significant increase of 90% arthritis in animals implanted with silicone elastomers. Animals implanted with silicone elastomer also developed foreign body sarcomas during the study. Serum concentrations of interleukin 10 were increased in mice implanted with elastomers and immunised with CII/FIA, while interleukin 5 concentrations were significantly diminished in these mice. The production of autoantibodies to autologous silicone bound proteins, including anti-type I collagen antibody, was also attributed to the implantation of either silicone gel or silicone elastomer in type II collagen immunised animals.

CONCLUSIONS

These data suggest that long term silicone implantation results in both the production of autoantibodies to connective tissue antigens and increased susceptibility to an experimental model of autoimmune disease.

An anti-inflammatory role for interleukin-11 in established murine collagen-induced arthritis

Interleukin-11 (IL-11) is a cytokine belonging to the IL-6 family which has both pro- and anti-inflammatory potential. Like IL-6 it can diminish tumour necrosis factor-alpha and IL-1 production, and augment immunoglobulin synthesis. We have explored the immunomodulatory effects of IL-11 treatment in mice in a model of inflammatory autoimmune joint disease, collagen-induced arthritis (CIA). Recombinant human IL-11 was administered at various doses to DBA/1 mice after the onset of CIA. IL-11 treatment caused a significant reduction in the clinical severity of established CIA, which was associated with protection from joint damage, as assessed by histology. Although there was a suggestion at high doses of IL-11 that the anticollagen type II (CII) response may have been augmented, there was no statistically significant effect of IL-11 treatment on anti-CII antibody levels. Similarly, the acute-phase reactant serum amyloid P was only elevated in mice receiving very high doses (50-100 microgram/day) of IL-11. Endogenous IL-11 was abundantly produced in synovial membrane cultures derived from CII-immunized mice with active disease, suggesting that, as in rheumatoid arthritis, this cytokine is spontaneously produced in the inflammatory response in CIA. The results presented here demonstrate an anti-arthritic immunoregulatory role for IL-11 in murine CIA, and suggest that IL-11 is a candidate therapeutic molecule for human inflammatory arthritic diseases.

The influence of silicone implantation on type II collagen-induced arthritis in mice

OBJECTIVE

To determine whether silicone implantation exacerbates autoimmune disease in a murine experimental model of arthritis.

METHODS

DBA/1 mice were implanted with silicone in the form of an elastomer, gel, or oil, and immunized with type II collagen. The influence of silicone implantation on collagen-induced arthritis and the immune response to type II collagen were determined by comparison against control mice receiving sham implantation. Adjuvant effects of silicone implantation were examined by measuring cytokine levels in implanted animals and assessing autoantibodies against proteins extracted from recovered silicone implants.

RESULTS

No adverse influence of silicone implantation on the clinical aspects of collagen-induced arthritis was observed. Further, polydimethylsiloxane silicone oil failed to serve as an adjuvant in the immune or arthritogenic response to type II collagen in mice. Cytokine analysis indicated that tumor necrosis factor alpha levels were lower and interleukin-2 levels were higher in silicone-implanted mice. The development of arthritis increased protein binding to implanted elastomers and gel, and autoantibodies against silicone-bound proteins were present in sera from arthritic mice and absent in sera from nonarthritic mice.

CONCLUSION

The data suggest that silicone implantation may result in autoantibodies against silicone-bound proteins, and the presence of arthritis may either provoke or increase the level of such autoantibodies. However, silicone implantation did not increase the incidence or severity of disease compared with sham-operated controls. Thus, it appears that autoantibodies against silicone-bound proteins may not have pathologic significance in this experimental model of arthritis.

Effect of IL-10 on collagen-induced arthritis in mice

In the present study we investigated the effect of a potent anti-inflammatory cytokine, interleukin (IL)-10, on the development of collagen-induced arthritis (CIA) in mice. Each DBA1/J mouse was immunized with 200 micrograms of native collagen and followed by booster injections at 3 weeks. rmIL-10 was injected i.p. daily at a dose of 100 ng/mouse. Mice were divided into four groups according to the administration period of rmIL-10. As a result, a 48-day course of IL-10 treatment significantly suppressed the severity of arthritis. Among the 4 groups, the most pronounced suppression was observed in the group in which IL-10 was given from day 0 to 21. On the other hand, there were no significant differences in the serum IgG anti-type II collagen (CII) titers between the four groups. Moreover, the production of cytokines (IL-6 and tumor necrosis factor-alpha (TNF-alpha)) and other mediators (prostaglandin E2 (PGE2) and nitric oxide (NO)) by peritoneal macrophages seemed to show no clear correlation with the severity of arthritis in mice. These results raise the possibility that IL-10 might be a useful agent for suppressing the progression and the development of CIA in mice.

Protective effects of D-penicillamine and a thiazole derivative, SM-8849, on pristane-induced arthritis in mice

To evaluate the antiarthritic properties of a novel thiazole derivative, the drugs SM-8849, D-penicillamine and indomethacin were administered to pristane-injected DBA/1 mice. The mice were treated daily with the agents for 32 weeks, starting from the day of the pristane injection. Treatment with SM-8849 (50 mg/kg) resulted in an amelioration of arthritic disease, as assessed by clinical, radiographic, and histologic examinations. Similar results were obtained in mice treated with 50 mg/kg D-penicillamine, although this disease modifying antirheumatic drug was slightly less effective than the same dose of SM-8849. In contrast, indomethacin at the maximum tolerated dose of 2 mg/kg did not alter the course of the disease. SM-8849 and D-penicillamine were also shown to reduce serum levels of rheumatoid factors and the acute-phase reactant, serum amyloid P component. Indomethacin failed to affect either parameter. Flow cytometric analysis revealed an elevation in the T-cell population that expressed CD44, a marker of murine memory T-cells, in spleens from pristane-injected mice. SM-8849, but not D-penicillamine, prevented the increase in this cell population. These results led us to conclude that pristine-induced arthritis was a useful model for the evaluation of antirheumatic agents, in that using this model, we were able to distinguish disease modifying antirheumatic drugs from nonsteroidal anti-inflammatory drugs. Our findings also indicate that SM-8849 shows antiarthritic activity, with a unique mechanism of action, differing from that of D-penicillamine.

Dietary n-3 fatty acids and arthritis

We have evidence that dietary fish oil (FO) decreases severity of collagen-induced arthritis (CIA), changes the fatty acid composition of macrophage (M phi) membrane phospholipids, decreases M phi synthesis of prostaglandins (PGs), changes chemotactic ability of M phi s, and affects metabolism of acute phase proteins. Gender also has pronounced effects on susceptibility to CIA and M phi prostaglandin profiles. The mechanisms by which dietary n-3 fatty acids may act to alleviate symptoms of CIA, as well as interactions of dietary n-3 and n-6 fatty acids and gender are discussed. We suggest that the ability of FO diets to influence favourably the course of chronic inflammatory diseases is mediated via alterations in n-6 fatty acid metabolism and that intrinsic differences in n-6 fatty acid metabolism may account not only for our reported gender differences in incidence and severity of CIA, but also the well-documented sexual dimorphism in immune/inflammatory responses in general.

Effect of inhibitors of eicosanoid metabolism in murine collagen-induced arthritis

The dual inhibitors of arachidonic acid metabolism, Smith Kline & French (SK&F) 86002, SK&F 104351, and phenidone; the corticosteroid, dexamethasone; and the selective cyclooxygenase inhibitors, ibuprofen, indomethacin, naproxen, and piroxicam were evaluated for their antiarthritic potency in the murine, collagen-induced arthritis model. The ability of these compounds to alter the severity of arthritic lesions and to reduce serum levels of the acute-phase reactant, serum amyloid P component (SAP) were monitored. Serum concentrations of SAP were found to correlate strongly (r = 0.985) with disease severity at day 35 postimmunization. Treatment with SK&F 86002, SK&F 104351, phenidone, or dexamethasone significantly reduced disease severity, as judged by clinical score (55%, 72%, 41%, and 45% inhibition, respectively) and SAP levels (62%, 94%, 52%, and 94% inhibition, respectively) in arthritic mice. This profile of activity was not shared by the selective cyclooxygenase inhibitors, which did not uniformly inhibit disease activity by both parameters. The results suggest that dual inhibitors of 5-lipoxygenase and cyclooxygenase may prove more effective than selective cyclooxygenase inhibitors as anti-arthritic agents.